Collection Simple Plus is a compilation CD album by Ali Project that compiles songs from the singles they had previously released under Victor Entertainment.

A limited edition version (catalog number: VIZL-198) has 12 tracks and a bonus DVD, containing the promo video for "Bōkoku Kakusei Catharsis" and a video clip of them performing "Gesshoku Grand Guignol" live.

The regular edition (catalog number: VICL-61999) has a thirteenth track, an orchestrated version of "Bōkoku Kakusei Catharsis".

7 on the Oricon charts and sold 45,616 copies in total.

All lyrics are written by Arika Takarano; all music is composed by Mikiya Katakura This article on a 2000s compilation album is a stub.